Field of the Invention
The present invention relates to the field of chemical technology of organosilicon compounds and can find an industrial application for preparation of novel functional materials, which possess luminescent properties. In particular, the invention relates to novel branched oligoarylsilanes.
Description of Related Art
As novel branched oligoarylsilanes within the current invention we mean the oligoarylsilanes, which are highly ordered spatially superbranched completely acyclic molecules in which two Si atoms are coupled to the central oligoaryl fragment, while each of the Si atoms is coupled with three other oligoaryl fragments, which possess a larger band gap (FIG. 1). As arylsilanes within the current invention we mean such compounds, which contain direct Si-aryl or Si-hetetoaryl bonds.
Either linear or branched arylsilanes are known, as well as based on them linear or branched polymers with arylsilane fragments in the main chain or as side substituents. In contrast with classic polyarylsilanes, novel branched oligoarylsilanes are individual compounds. This fact allows their isolation with a high degree of purity available for low molecular weight compounds. This is especially important for their application in organic photonics and electronics. The specific 3D architecture of such molecules provides them a number of valuable properties, such as good solubility and ability of films formation in combination with the possibility to tune their optical and electrical properties by means of molecular design.
Branched oligoarylsilanes, described within the present invention, have a molecular structure close to that of aromatic dendrimers, exhibiting luminescent properties. Organic light emitting dendrimers and devices based on them are known, for instance, from European patent EP 1027398 B1, 2004, U.S. Pat. No. 6,558,818 B1, 2003 and U.S. Pat. No. 6,720,093 B2, 2004. The dendrimers applied may contain organosilicon fragments as well as heteroaryl fragments. However, synthesis of the dendrimers is quite a time-consuming and expensive process.
Similar molecular structure to those of the branched oligoarylsilanes claimed have oligoarylsilanes A (Adv. Funct. Mater. 2005. 15. 1799-1805) and B (Organic Electronics 8 (2007) 349-356), having the following structural formula:
which may be represented as a general formula (A-1) and (B-1):

In structures A and B two silicon atoms are linked to the central oligoaryl fragment, while each of the silicon atoms is linked to three aryl (phenyl) fragments. In contrast to oligoarylsilanes A and B, within the present invention we claim oligoarylsilanes, possessing specific optical properties due to the presence of three oligoaryl fragments attached to each silicon atom. Moreover, the claimed compounds, in contrast to the known analogues, contain terminal groups R, which improve significantly solubility of the oligoarylsilanes.
The closest structural analogue of the novel branched oligoarylsilanes claimed are branched oligoarylsilanes of the following general formula (Patent RU 2396290):

Such oligoarylsilanes apart from the central oligoaryl fragment contain two other oligoaryl fragments Arn, which are linked to each silicon atom.